I wasn't blaming the BBC. Genuinely interested if you had any insight. Presumably there is some negotiation/agreement between the the football authorities and broadcasters.

Only insofar as the Football League have prioritised selling subscriptions to Seagulls Player etc etc. so restrict the BBC rights.
BBC have chunked up their progs this season so make , for example the post match phone in / interview/highlights programmes available but they haven't ever had these live match commentary rights to my knowledge.
If a commentary is on 5 Live or 5 Live sports extra then its available in the UK online. this sometimes means the odd Albion games. (usually the ones on Sky)
But if all BBC commentaries were available online then i doubt subs for the Players would have much appeal.